Air Handler Design for Modular Manufacturing of High Performance and No Shutdown Units

ABSTRACT

This patent application covers design and modular manufacturing techniques for an economical air handler and exhaust fan product line that delivers better energy performance, acoustical performance, space utilization, and operational efficiency than is available in today&#39;s marketplace. An axial fan is positioned within airflow guides designed to minimize turbulence to reduce acoustics and energy consumption. The specific arrangement of air filters, heating and cooling coils, airflow guides, sound attenuating surfaces, fan modules, control panels, backdraft dampers and isolation dampers enables the stacking of modular units to meet air handler capacity requirements with inherent redundancy. In some configurations, the air handler described provides complete redundancy for a no-shutdown system that will reduce HVAC energy requirements to a lower level and provide a greater operating range than is available in today&#39;s market.

BACKGROUND

Air handlers combine fans with thermally active components to deliver specific quantities and qualities of air. The air handler industry has evolved to offer products predominantly using centrifugal fans because they are easier to configure and assemble in diverse HVAC application. However, axial fans have the potential to provide better performance and efficiency if designed and configured properly. Axial fans are uncommon in air handler manufacturing due to the complex aerodynamic challenges that often result in excessive noise and the potential for extreme turbulence that reduces fan performance efficiency. In the past, some air handler manufacturers offered axial fan air handlers that operated much more efficiently than mass produced air handlers. However these products are not available in today's market because of the high cost of custom manufacturing, and the difficulties of engineering an efficiently designed axial fan system. With increasing awareness of energy and environmental issues, a highly efficient and cost effective axial fan air handler product is needed by the marketplace. This patent covers the design and product line marketing strategies for a modular line of axial fan air handling products with interchangeable components to address a wide variety of applications with more energy efficiency, quieter operation, and a greater operating range than other options available in today's marketplace.

SUMMARY

This patent covers an air handler and fan modular manufacturing system to provide unique energy efficiency and operational improvements at an economical cost. A specific feature of this air handler series design (AxHU) is the use of axial fans in a modular approach (Axial Fan Modules) that can be combined together in a stack, line or grid or array arrangement and combined with flow straighteners, acoustic attenuating surfaces, return air pathways, control panels, sensors, instruments, air filters and heat exchange coils to comprise an air handler. The specific arrangement of components described here provides a low profile air handler that can be stacked to provide the capacity needed for each application. This results in an air handler (AxHU) made up of multiple sections (Blades) that together can provide complete redundancy in case of any single component failure for an air handler that will never need to shut down, which is very valuable for critical facilities such as hospitals, labs, cleanrooms and datacenters. A version of the AxHU uses VFDs, software controlled, or ECM motors with axial and/or centrifugal fans to serve in certain configurations where they are most appropriate. Manufacturing cost savings come from using mass produced instead of custom-built components by producing only a few sizes of fan modules and combining them to meet the specific required capacities. The AxHU overcomes the aerodynamic challenges of axial fan operation in a fan module that can be arranged in an array or grid to support an economical modular manufacturing operation. Also, the fan modules can be used in an exhaust, return, in-line or plenum fan application for economic manufacturing operation. The intake and discharge sections can be modified to meet the desired capacity for each application. This AxHU system is unique because the specific arrangement of components allows for a lower overall pressure drop and efficiency level without large increases in equipment capital costs, and comprises an air handling system with complete redundancy. The modular design also allows the sequential staging of each Blade to produce a much wider airflow operating range to address challenges where extremely low airflow levels are needed. Together these design features comprise an fan system with lower capital costs, equipment footprints, acoustical levels, power requirements, and service costs while providing improved reliability, redundancy, and operating range. These benefits are only achieved through the axial fan modular designs and specific configurations described in this patent.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1: AxHU Blade with 100% Outside Air, Top View

FIG. 2: AxHU Blade with Return Fan and Double Fans

FIG. 3: AxHU Blade with Reconfigured Return Air

FIG. 4: AxHU Blade with Final Filters

FIG. 5: AxHU with three Blades Side Views

FIG. 6: Axial Fan Module

FIG. 7: Multiple Axial Fan Modules

FIG. 8: Nose Cone Options

FIG. 9: Head Section

FIG. 10: Alternate AxHU Configurations

FIG. 11: Vertical AxHU Configurations

FIG. 12: Alternate Configurations—Axial Fan Module Arrays

FIG. 13: More Alternate AxHU Configurations

FIG. 14: Polaris AxHU Configurations

FIG. 15: Data Module AxHU Configurations

FIG. 16: Axial Fan Module In-line or Exhaust Fan Options

FIG. 17: Axial Fan Module In-line or Exhaust Fan Options

FIG. 18: Plenum Exhaust Fan Configurations

FIG. 19: Axial Fan Module Supply Fan

FIG. 20: Axial Fan Module Plenum Fan

FIG. 21: Axial Fan Module Alternate Taper

FIG. 22: Discharge Section—Plenum

DETAILED DESCRIPTION

FIG. 1—AxHU Blade with 100% Outside Air: The AxHU air handling components are shown in a cutaway view shown from the top in the basic arrangement, which is approximately 10′ wide by 20′ long by 30″ tall. The height of this unit accommodates a 24″ tall air filter, and this unit is called a Blade. Each Blade operates independently and is designed to stack upon each other to meet the desired total capacity requirements for the AxHU so if any component on one Blade fails, it can be isolated automatically and the other Blades will increase in speed to meet he required capacity. The Blades are designed to be automatically isolated from the HVAC system upon a fan failure, then the fan module can be manually isolated for repair or replacement while the AxHU continues to function. Outside air enters through the Outside Air Intake 1 and is pulled through the Control Dampers 2, Air Filters 4, Optional Heating Coil 5 and Cooling Coils 6, which can be provided with two independently operating cooling coils to provide a wide range of temperature and humidity levels. If required for the application, return air can enter the Blade from the Return Air Control Damper 3 through an Air Filter 4 to mix with he outside air, then pass through the Optional Humidifier 7. The air flows next through a Flow Straightener 14 then turns 180 degrees through the Head Section 17 then more Flow Straighteners 14. The air then is pulled through the Fan Module 16 on to the Discharge Section 15, in which a Optional Humidifier 10 may be located. On either side of the Fan Module 16 are Manual or Automated Isolation Dampers 11, which consist of a sheet metal piece the size of the Fan Module 16 housing with rubber, nylon or similar material seals around the perimeter. This sheet metal Isolation Damper 11 can be slid manually into place when needed to isolate the Fan Module 16 when a repair or replacement is needed while the AxHU remains in service. After the supply air passes through the Discharge Section 15, it passes through an automatic Backdraft Damper 9 as it goes on to the ductwork or distribution system.

FIG. 2—AxHU Blade with Return Fan and Double Fans: This diagram shows another version of Blade configured for a system using return air, which enters through an optional Return Air or Relief Air Fan 18 section. FIG. 2 also shows an option designed for more power or pressure requirements by being provided with Dual Fan Modules 19. Everything else in FIG. 2 matches the descriptions listed for FIG. 1.

FIG. 3—AxHU Blade with Reconfigured Return Air: This diagram shows an alternate arrangement of the Optional Heating 20 and Dual Cooling Coils 21, with everything else shown matches previous descriptions.

FIG. 4—AxHU Blade with Final Filters: This diagram shows a Blade equipped with a location for a return air duct or optional access door 22 and a added Discharge Head Section 23 with associated Flow Straighteners 24 and a rack carrying Final Filters 25 that the Discharge Air 26 passes through. This diagram shows a set of Sealed Doors 27 for access to the Final Filters 25 for servicing.

FIG. 5—AxHU with three Blades Side Views: This shows the side view for an AxHU consisting of three Blades 34 vertically stacked. On the upper detail showing the Intake Side View, the air enters the AxHU from the Outside Air Filters 29 and then passes through the coils and the Head Sections 28 on the left side of this view. On the lower view showing the discharge side of the AxHU, the air passes through Head Section 33 and the flow accelerators on its way to the Fans 32 then on to the Discharge Section 31. Each Blade is divided metal airtight sheets called the Optional Dividers 35 in the AxHU configuration designed for complete redundancy so each Blade can operate independently of the others.

FIG. 6—Axial Fan Module: Each Axial Fan Module minimizes turbulence with airflow guides forming the Accelerator with Perforated Sound Attenuator section 44 on the entry side of the Intake Section 42 side of the Fan 39 which is surrounded by Nosecones 36 designed to minimize turbulence by avoiding boundary later separation. The Nosecone 36 on the inlet side of the Fan Hub 40 is larger diameter than the Nosecone 36 on the discharge side of the fan when the Fan Motor 41 is of a smaller diameter than the Fan Hub 40. After the air passes through the Discharge Section 43, which is housed in a Square to Round Transition 37 for the AxHU configuration, it enters the Decelerator Transition 38 to slow the air down and increase its static pressure through static regain design principles according to the desired discharge conditions. The lower view of FIG. 6 is a Top View to show the detail of turbulence minimizing Sharp Leading Edges on the Airflow Guides 45 in the Accelerator With Perforated Sound Attenuator 44. This view shows the Removable Isolated Fan Mountings 47 needed to be able to remove and service or replace the fan and motor if needed. The Control Panel 46 is shown adjacent to the Fan so these are easily accessible in the AxHU air handler design. There is a Square to Round Transition 48 and Optional Isolation Damper 49 on either side of the fan which enables the servicing of an individual fan while the remaining Blades continue to function. As the air leaves the Fan 39 through the Square to Round Transition 48 in the Discharge Section 43, turbulence is minimized with the airflow guides in the Decelerator Transition 38 that can be equipped with a Backdraft Damper 50 if appropriate for the specific application. The Fan 39 is mounted on springs or snubbers for vibration and acoustical isolation. The Nosecones 36 are specially shaped to match the square to round interior of the Intake Section 42 and Discharge Section 43 to reduce the overall length of the AxHU. Each axial fan assembly has an integrated Control Panel 46 with an internal divider between the high voltage and low voltage sections, and a vent connected to the pressurized Discharge Section 43 to provide continuous cooling and clean air for the electronics. The axial fan assembly is built to enable individual rapid fan removal and replacement with minimal operational disruptions (no disruptions for the Polaris model), and the control panels are equipped with a multi-pin connector to enable rapid replacement. On either side of the fan are isolation dampers, either manual or automatically actuated, to enable the replacement of a single fan without impacting the continuous performance of the air handler.

FIG. 7—Multiple Axial Fan Modules: This diagram depicts fans arranged in series for applications requiring higher air pressures. There are Intermediate Nosecones 52 between fans in series to minimize turbulence with a discharge Nosecone 51 of a different configuration on the final fan motor. The Ax2 53 is shown utilizing two fans in series in the upper view, and the lower view shows three fans in series for the Ax3 54 configuration. The Axial Fan Modules are combined to meet the desired capacity with sufficient oversizing for redundancy appropriate for the applications.

FIG. 8—Nose Cone Options: Various shapes of Tapered Nosecones 55, Round Nosecones 56, Round to Tapered Square Transition for Nosecone 57 (End View of Round to Square Nosecone 58 shown in detail view), and Alternate Nosecone Configurations 59 which are needed to accommodate specific types of fan motors. The Round to Tapered Square with Outer Guide Transition for Nosecone 57 is shown as a side view with the Outer Guide consisting of a square to round duct with a more gradual taper than the nosecone within the square to round shaped AxHU housing to reduce the length of the overall AxHU, saving material, equipment space and further reducing acoustical noise.

FIG. 9—Head Section: At the end of each Blade, the Head Section 60 turns the airflow 180 degrees without boundary layer separation and turbulence to accelerate the air to approximately twice the velocity. This uses specially designed Optional Flow Straighteners and Acoustical Attenuators 61 and Airflow Guides 62 that are circular or other optimized curved shape to turn the airflow without turbulence 63. The Head Section can be removable to allow servicing and cleaning.

FIG. 10—Alternate AxHU Configurations: Various configurations of AxHUs will be designed for special applications that do not allow the usage of the basic horizontally arranged Blades. The AxLine 64 consists of air intake Coils and Filters 66 on either vertical face with the Axial Fan Modules 65 located on top using a specially designed Head Section. The AxStax 67 has air intake Coils and Filters 69 located on either vertical side for air intakes with the Axial Fan Modules 68 located in the middle in a vertical stack. The Three Sided AxStax 70 is similar to the AxStax with a Return Air Inlet with Filters Only 71 located on the top part of the AxHU.

FIG. 11—Vertical AxHU Configurations: Other options for AxHU applications are a Vertical Blade 74 with a side air intake through Filters 76 and Coils 77 at the lower portion and the Axial Fan Module 75 located towards the middle. The Double Vertical Blade 78 is a similar arrangement to the Vertical Blade with air intake on both sides and twice the capacity output with redundancy capabilities. The Alternate Double Vertical Blade 79 is similar to the Double Vertical Blade 78 except with air intakes located on one side only.

FIG. 12—Alternate Configurations—Axial Fan Module Arrays: This diagram shows Axial Fan Module Arrays for use as transfer or other stand alone fan applications. The Ax Stack 80, the Ax Grid 81 and Ax Matrix 82 show different ways the Axial Fan Modules can be arranged for different applications with larger numbers of fans possible as the application requires. These will be longer than some centrifugal fan options, but will be quieter and more energy efficient than other designs available for similar applications.

FIG. 13—More Alternate AxHU Configurations: This diagram shows more arrangement possible for specific applications including Double AxStax 83 with Optional Filters on Ceiling 84, and Polaris No Shutdown Version 87 for critical facilities that never shutdown even for servicing. This version has Blades in Isolatable Sections 88 and Control Panel Access 89 arranged for easy operation.

FIG. 14—Polaris AxHU Configurations: This diagram shows the Double Polaris No Shutdown Version 90 with Air Filters 91, Coils 92, Blades in Isolatable Sections 93, central Access Door for maintenance and control 94 for access to the Control Panels 95 inside the unit. Also shown here are the Fan Modules 96 located on either side of the central access area.

FIG. 15—Data Module AxHU Configurations: This diagram shows configurations tailored to datacenter modular applications with Prefabricated AxHU for Data Modules 97 with interior mounted IT Racks 98 cooled by the coils and filters. This design can be made for 100% outside air or recirculated air in any desired proportions.

FIG. 16—Axial Fan Module In-line or Exhaust Fan Options: This diagram shows an In-line fan with approximately 2500 feet per minute airflow for a 24″ diameter discharge duct 99.

FIG. 17—Axial Fan Module In-line or Exhaust Fan Options: This diagram shows an exhaust fan configuration with Accelerator Section with sound attenuating materials 100, then an Isolation Damper 101 leading to the Fan then the Deceleration Section 102 and the Sound Attenuators Flow Straightener 103 at the discharge end.

FIG. 18—Plenum Exhaust Fan Configurations: This diagram shows a Plenum Exhaust Fan with a wide area of Sound Attenuators Flow Straightener with Rounded Corners 107 for the intake air and Optional Backdraft Dampers 108 for applications requiring low noise output. The air then travels through the Accelerator Section with Sound Attenuators 105 and Airflow Guides with Rounded Corners 104 at Angle A 106 that will be designed for minimum turbulence.

FIG. 19—Axial Fan Module Supply Fan: This diagram shows a Supply Fan 109 application for the axial fan module fitted with sound attenuators and airflow guides.

FIG. 20—Axial Fan Module Plenum Fan: This diagram shows a Supply Fan 110 with larger discharge area for specific applications. This view shows an Optional Backdraft Damper 111 at the discharge end.

FIG. 21—Axial Fan Module Alternate Taper: This diagram shows an Axial Fan Module 112 with a specially designed taper and nosecone to enable a shorter overall length and quieter operation.

FIG. 22—Discharge Section—Plenum: This diagram shows a Discharge Section Plenum 113 in detail with Airflow Guides 114 and Optional Manual Isolation and/or Backdraft Damper 115 and Optional Airflow Straightener and Sound Attenuators 116.

Blade: The combination of the air filters, coils, head, end sections, Axial Fan Modules, piping, and controls comprises a Blade in different standardized sizes to be combined to form an air handler comprised of a Blade stack or row. Together, the sizes of the Blades will be combined to accommodate any system capacity desired while supporting economical modularized manufacturing with repeatedly used components. As the AxHU ramps through its designed discharge range to meet the system demand, the axial fan assemblies are staged on and off to maintain the most efficient operation the overall fan system while avoiding a stall condition from any single fan using the automatic isolation dampers to stage the fans properly. The isolation dampers, automatic, backdraft or manual, will isolate and enable the replacement of a single fan while the entire AxHU remains in operation without interruption of service. For critical facility units, an entirely cleanable wash-down AxHU version enables the servicing of all components without a loss or disruption of operational service. The layout of the blade design follows the Constructal Law parameters to make equal time spent for the air to traverse each segment of the blade with an overall design focus of minimizing energy losses. As another alternative design, the acceleration may be completely handled by the Head section with little airflow acceleration done by the airflow guides on the inlet to the Axial Fan Module.

AxHU: Various amounts of equal sized blades are combined to meet specific capacity and redundancy requirements to form an AxHU. An airflow straightener transition section is included on either side of the fan array as needed to meet the application requirements with a minimum of turbulence. The airflow accelerator and deceleration sections utilize a Constructal Law guided design for the minimization of turbulence, boundary layer separation and best energy performance. The development and further refinement of the acceleration and deceleration section designs will be guided by aerodynamic analysis and empirical testing. A version of the accelerator section uses airflow separators in line with the air movement that gradually expand each section symmetrically in a gradual flare. The Axial Fan Modules transition into a head section that turns the airflow without turbulence to create a compact air handler unit. The most common configuration of the head section is a 90 to 180 degree redirection of the airflow incorporating an airflow acceleration, acoustical dampening, and flow straightening function. This head section reroutes and accelerates the air, dampens acoustical energy, and can be configured with an optional access door for maintenance purposes. The head section transitions the air from the filter and coil section, which can be on one, two, three, four or five sides of the air handler. This correlates to the use of a head section that is one, two, three or four sided, however the single and double sided head sections are the most commonly used for economical mass production. The head section can be made with single or multiple layers of perorated metal or plastic guides incorporating an optional plastic, kynar, nylon, mylar, fiberglas, mineral wool, or other similar material liner designed to absorb acoustical energy. The airflow guides in the head section are fabricated in simple geometric shapes including circles and elongated circles for ease of manufacturing with guides, supports and spacers that can be mass-produced and used for all sizes of air handlers and fans. Other optional head sections have specially shaped airflow guides designed to optimize energy performance and minimize space requirements using parabolic or other shapes tailored for custom applications. An option is to use rounded guides that decrease the angle of air curvature in proportion to the inertia or momentum of the accelerating or decelerating air flow.

The filter/coil section is designed to distribute the air evenly, minimize pressure drop and turbulence, and provide easy access for maintenance purposes. All corners and transition sections of the AxHU have smooth, rounded corners to minimize turbulence generation. The cooling and heating coils are placed back to back with the header piping located in a downstream location over the drain pan, which can be made of stainless steel or with anti-microbial materials as an option (either silver impregnated stainless steel, copper, plastic, or a specially coated metal surface). As an option, the entire interior of the AxHU can be made of anti-microbial materials, and with optional UV lighting. The length of the AxHU will be determined by the desired pressure drop from the air filters and coils, and the airflow pathways will be designed to minimize turbulence and pressure drops with smooth surfaces and transitions between sections. Other options are a unit made entirely of non-ferrous materials.

Opposite the head section is the end, usually the discharge end and the return air intake. The return air intake can enter the AxHU from the end, side or top, and an access door can be installed in the end for many configurations. The discharge end of each axial fan assembly has airflow expanders that decelerate the air without causing turbulence or significant boundary layer separation. Additionally, there will be a final flow straightening section at the discharge end of the axial fan assemblies consisting of straight vanes or grids, rectangular mesh or hexagonal structures to minimize the possibility of system effects resulting from improper field installations. For the Operationally Efficient Package, provisions for the complete isolation of each blade's filter and coil section enables the changing of filters without impacting the controlled environments being served. In the end section, a specialized shut-off panel system engages to maintain stable operations when a single fan needs to be shut down and isolated. This results in an affordable fully redundant air handler system that never needs shutdowns for its entire service life.

The floor of the air handler will range from an inexpensive sheet metal surface to a cleanable, stainless steel basin with an interior designed for wash down applications for clean facilities. The access doors and closure panels will be sealed tightly to minimize air leakage. The AxHU enclosure will be sealed tight with a thermal break construction for outdoor applications. High performance double and triple gasketed doors available for critical facilities. Each section will come with optional sealed drains and sealed conduit penetration for future upgrades needed.

As an alternate to the head section design, a sheetmetal coil wound in a spiral would create the accelerating airflow needed for the axial fan inlet in an intake plenum. This may be a segmented spiral made of 3, 5, 7, or 11, or other prime number of straight airflow guides that produces a doubling of surface area while preventing significant air boundary layer separation. This air accelerator coil will have rigid supports spanning the intake and discharge ends to stabilize the airflow guides. These supports will have a slant built into them to pre-rotate the air stream in the direction of fan rotation at an angle determined to optimize fan performance. This and many other features are designed to improve the overall fan assembly performance resulting in ‘negative system effects’, which is fan performance that exceeds AMCA test results.

The AxHU can be made in a 100% outside air supply fan configuration, or with a return or relief fan section for commercial applications. The return ductwork connects to a section outside of the air filters next to the fresh air inlet section. Dampers control the amount of outside air versus return air for a modulating economizer function. An optional configuration has the air filters and thermal coils mounted at an angle in the vertical plane to accommodate a return air connection into a mixed air section. Also, the mixed air section can be configured with a humidifier for tightly controlled environments. The economizer components are made with corrosion resistant materials and sealed from the environment. Another version of the AxHU is configured with a final filter section including HEPA and ULPA filters. In this arrangement, the deceleration section is followed by another head section that slows down the air gradually and routes it into an oversized discharge section upstream of the final filters to support energy efficient operation. For applications that have space constraints, the return fan can be located in the ductwork independently of the AxHU.

The Axial Fan Module or Modules can be configured as an exhaust or transfer fan product with an exhaust plenum accelerator option. Many Axial Fan Modules can be combined as a fan manifold that stage on and off to maintain desired service with a minimum of energy consumption. Options include a controllable air bypass damper and anemometer based speed control.

Sensors and instruments are included since they are important to ensuring the proper functioning and maintenance of the HVAC system operations. AxHUs are tailored for different markets requiring specialized automation options. Three levels of AxHU instrumentation are offered in the basic, the energy efficient, and the operationally efficient packages.

The Basic Instrumentation Package includes manual air filter differential pressure gauges, fan failure alarms, and fan motor drive interface to BAS. The Operationally Efficient Package adds remote monitoring for air filter differential pressure, vibration monitoring, airflow monitor, current sensors and outdoor airflow monitor. Along with other specialized AxHU features, the Operationally Efficient Package delivers continuous uninterrupted HVAC service without disruptions for maintenance operations, which is important for critical facilities. The Energy Efficient Package includes added temperature differential across coils (air and water side), differential pressure across the fan assemblies, airflow monitor, motor amperage power readings, alarm records, and a differential pressure across the entire AxHU.

The AxHU line will be designed for three different general applications:

1. Office=Atlas

2. Laboratory=Stratus

3. Cleanroom=Polaris

Each line will have standard features and special upgrades and options tailored to their market. The Atlas will have a tightly sealed cabinet with options for spare conduit penetrations. Stratus will have strengthened cabinet with a checkerplate flooring turned up at the edges to hold standing water. There will be an optional floor drain in each section with a tightly sealed screwed cap daylighting to the exterior of the AxHU base. The Polaris will be specialized for cleanroom and healthcare applications with cleanable, no gap interior, continuous no-shutdown design, and deluxe automation package.

Feature Atlas Stratus Polaris Strengthened cabinet ◯ X X Outdoor package ◯ ◯ ◯ Acoustical attenuation package ◯ ◯ ◯ Sealed motor bearings X X X No bypass air filter frame ◯ X X Vibration monitors ◯ ◯ ◯ Air filter/coil differential pressure gauge X X X Air filter/coil photohelic pressure gauge ◯ ◯ ◯ Light weight materials ◯ ◯ ◯ Non-ferrous materials ◯ ◯ Anti-microbial drainpan and coatings ◯ X UV Lights ◯ ◯ ◯ Checkerplate flooring with turned edges X X Sealable interior drains ◯ X Double gasketed doors X X Sealed 2″ conduits for each section ◯ ◯ X Automatic fan isolation dampers ◯ ◯ ◯ Entire AHU differential pressure monitor ◯ ◯ X Individual fan current monitoring and alarms ◯ ◯ X Washdown interior X Hydrophobic coating on coils ◯ ◯ ◯ Basic Instrumentation Package X X X Energy Efficient Instrument Package ◯ ◯ ◯ Operationally Efficient Instrument Package ◯ ◯ ◯ Isolation of each blade's filter and coil section ◯ ◯ Isolation dampers downstream of Fan Modules ◯ ◯ 

1. Modular air handler manufacturing line using axial or centrifugal fan standardized componentry combined to meet required applications with specializations for different markets. The most common AxHU layout (horizontal Blade) consists of a low cost modular fan assembly with a low pressure drop filter and coil section and an easily accessible control panel that allows for the rapid removal and isolation of an individual fan and motor. Additionally, an alternate configuration involving a 90-degree re-orientation of the control panels, filters and coils enables the Blade to be mounted in a vertical instead of horizontal position. a. Modular AHU and Fan system using axial fan modules designed for minimum turbulence and acoustics. b. Different fans can be provided for different system capacity requirements without changing other parts of the AxHU. The fans will be assembled in modules that can be included with different filter, coil, and airflow guide configurations for different applications. c. Main component is the Axial Fan Module, which includes the fan, housing, isolation dampers, nosecones, airflow guides, sound attenuators, backdraft dampers, and power and control panel. d. The nosecones on the intake and the discharge side of the fans may be similar or different design from each other to minimize energy consumption. The nosecones will be a conical or square-to-round shape to match the intake and discharge duct square-to-round sections. The nosecone surfaces and surrounding duct sections may have acoustically absorbing surface finish or perforations. An intermediate concentric cylindrical airflow guide will be used surrounding the nosecones to improve airflow stability in some configurations. This cylindrical airflow guide may be eliminated for the fan intake section to take advantage of the cost benefits of using a modular product line approach. e. The Axial Fan Module can be used as a supply, return, exhaust, in-line, or plenum fan in a stand-alone or in combination with others in a row, stack, in-series, or grid configurations. They can be provided with multiple Axial Fan Modules in series with intermediate nosecones for higher pressure applications. f. The Axial Fan Module combined with other airflow control and thermally active components, controls and sensors comprises a Blade, which can be stacked vertically or horizontally to meet the required Air Handler (AxHU) capacity. g. The discharge decelerator sections are available in different interconnecting options for different applications, such as in-line, shaft discharge, or plenum, and for different discharge airflow requirements. h. The air intake section for each Blade uses a row or rows of air filters designed for low velocity airflow, followed by optional preheating, cooling and optional reheating coils, UV lights and other optional systems as needed for each application. i. Each fan module control panels will be mounted on the outside of the AxHU in some configurations to enable the stacking of each independent Blade section. j. Refrigeration section may be included in the AxHU attached to the End Section. 2-14. (canceled) 